The big advantage of cash envelopes is that, if you budget properly, you will always have the cash to pay a bill when it comes due. No more worrying about where the money will come from, be it for mortgage or rent, utilities, car payments, repairs, taxes, discretionary spending, etc.
I've found that when creating a budgeting worksheet the best way to start is with a set up like this; _ Firstly, place your pay dates along the top (shown from A1 to G1). These can be weekly, fortnightly or monthly or any period that you normally work from. _ Then list out each income source and the amounts you receive from them. For irregular payments such as Christmas bonuses etc set up a row specifically for this and maybe name it "Other Income".